吉林蛟河针阔混交林林层结构对生产力的影响

Influence of forest strate structure on productivity of coniferous and broad-leaved mixed forest in Jiaohe,Jilin

探讨不同林层物种多样性和林分结构与森林生产力之间的关系,为森林可持续经营管理策略优化提供理论支持。以吉林蛟河30 hm^(2)针阔混交林固定监测样地中的38432株木本植物的野外调查数据为研究对象,利用结构方程模型探讨了不同林层物种多样性和林分结构多样性对森林生产力的作用机制。结果表明:(1)林冠层林分结构多样性和生产力之间呈负相关关系,路径系数为-0.138;林下层林分结构多样性和生产力之间呈正相关关系,路径系数为0.083。(2)林冠层物种多样性和生产力之间呈正相关关系,路径系数为0.099;林下层物种多样性和生产力之间关系不显著,且物种多样性在林冠层和林下层呈正相关关系,路径系数为0.147。物种多样性和林分结构多样性与森林生产力之间不存在唯一的关系,这种关系的大小、方向和潜在机制与林层有关。为此,在森林经营过程中要充分考虑不同林层物种多样性和林分结构多样性与森林生产力之间的关系。

The objective of this paper is to study the relationship between species diversity,stand structure and forest productivity across forest strata which provides theoretical support for sustainable forest management strategies.The coniferous and broad-leaved mixed forest in Jiaohe of Jilin Province was taken as the research object,based on the field survey data of 38432 woody plants in the 30 hm^(2)fixed monitoring plot.The structural equation model was used to study the mechanism of forest productivity based on species diversity and stand structure diversity across forest strata.The results show that:(1)overstorey stand structure diversity had the negatively direct effects on productivity,with a path coefficient of-0.138.But understorey stand structure diversity had the positively direct effects on productivity,with a path coefficient of 0.083.(2)Overstorey species diversity had the positively direct effects on productivity,with a path coefficient of 0.099.The relationship between species diversity and productivity in understorey was not significant,and overstorey species diversity significantly promoted the understorey species diversity,with a path coefficient of 0.147.This study suggests that no sole and ubiquitous relationship between species diversity,forest structure and forest productivity,but rather that the magnitude and direction of this relationship is greatly dependent on the forest strata.Therefore,the relationship between the species diversity,stand structure diversity and forest productivity across different forest strata must be fully considered in the forest management process.